/*
 * Copyright (C) 2008-2014 TrinityCore <http://www.trinitycore.org/>
 * Copyright (C) 2006-2009 ScriptDev2 <https://scriptdev2.svn.sourceforge.net/>
 *
 * This program is free software; you can redistribute it and/or modify it
 * under the terms of the GNU General Public License as published by the
 * Free Software Foundation; either version 2 of the License, or (at your
 * option) any later version.
 *
 * This program is distributed in the hope that it will be useful, but WITHOUT
 * ANY WARRANTY; without even the implied warranty of MERCHANTABILITY or
 * FITNESS FOR A PARTICULAR PURPOSE. See the GNU General Public License for
 * more details.
 *
 * You should have received a copy of the GNU General Public License along
 * with this program. If not, see <http://www.gnu.org/licenses/>.
 */

#ifndef SCRIPTEDCREATURE_H_
#define SCRIPTEDCREATURE_H_

#include "Creature.h"
#include "CreatureAI.h"
#include "CreatureAIImpl.h"
#include "InstanceScript.h"

#define CAST_AI(a, b)   (dynamic_cast<a*>(b))
#define ENSURE_AI(a,b)  (EnsureAI<a>(b))

template<class T, class U>
T* EnsureAI(U* ai)
{
    T* cast_ai = dynamic_cast<T*>(ai);
    ASSERT(cast_ai);
    return cast_ai;
};

class InstanceScript;

class GAME_API SummonList
{
public:
    typedef GuidList StorageType;
    typedef StorageType::iterator iterator;
    typedef StorageType::const_iterator const_iterator;
    typedef StorageType::size_type size_type;
    typedef StorageType::value_type value_type;

    explicit SummonList(Creature* creature)
        : me(creature)
    { }

    // And here we see a problem of original inheritance approach. People started
    // to exploit presence of std::list members, so I have to provide wrappers

    iterator begin()
    {
        return storage_.begin();
    }

    const_iterator begin() const
    {
        return storage_.begin();
    }

    iterator end()
    {
        return storage_.end();
    }

    const_iterator end() const
    {
        return storage_.end();
    }

    iterator erase(iterator i)
    {
        return storage_.erase(i);
    }

    bool empty() const
    {
        return storage_.empty();
    }

    size_type size() const
    {
        return storage_.size();
    }

    void clear()
    {
        storage_.clear();
    }

    void Summon(Creature const* summon) { storage_.push_back(summon->GetGUID()); }
    void Despawn(Creature const* summon) { storage_.remove(summon->GetGUID()); }
    void DespawnEntry(uint32 entry);
    void DespawnAll();

    template <typename T>
    void DespawnIf(T const &predicate)
    {
        storage_.remove_if(predicate);
    }

    template <class Predicate>
    void DoAction(int32 info, Predicate&& predicate, uint16 max = 0)
    {
        // We need to use a copy of SummonList here, otherwise original SummonList would be modified
        StorageType listCopy = storage_;
        Trinity::Containers::RandomResize<StorageType, Predicate>(listCopy, std::forward<Predicate>(predicate), max);
        for (StorageType::iterator i = listCopy.begin(); i != listCopy.end(); )
        {
            Creature* summon = ObjectAccessor::GetCreature(*me, *i++);
            if (summon && summon->IsAIEnabled)
                summon->AI()->DoAction(info);
        }
    }

    void DoZoneInCombat(uint32 entry = 0, float maxRangeToNearestTarget = 250.0f);
    void RemoveNotExisting();
    bool HasEntry(uint32 entry) const;

private:
    Creature* me;
    StorageType storage_;
};

class EntryCheckPredicate
{
    public:
        EntryCheckPredicate(uint32 entry) : _entry(entry) { }
        bool operator()(ObjectGuid guid) { return guid.GetEntry() == _entry; }

    private:
        uint32 _entry;
};

class DummyEntryCheckPredicate
{
    public:
        bool operator()(ObjectGuid) { return true; }
};

struct GAME_API ScriptedAI : public CreatureAI
{
    explicit ScriptedAI(Creature* creature);
    virtual ~ScriptedAI() { }

    // *************
    //CreatureAI Functions
    // *************

    void AttackStartNoMove(Unit* target);

    // Called at any Damage from any attacker (before damage apply)
    void DamageTaken(Unit* /*attacker*/, uint32& /*damage*/) override { }

    //Called at World update tick
    virtual void UpdateAI(uint32 diff) override;

    //Called at creature death
    void JustDied(Unit* /*killer*/) override { }

    //Called at creature killing another unit
    void KilledUnit(Unit* /*victim*/) override { }

    // Called when the creature summon successfully other creature
    void JustSummoned(Creature* /*summon*/) override { }

    // Called when a summoned creature is despawned
    void SummonedCreatureDespawn(Creature* /*summon*/) override { }

    // Called before hit by a spell. Damage is represented by a positive value, healing by a negative one.
    // Note that this is called before DamageTaken(...) so the damage can still be modified.
    // Note that the healing can still be reduced by heal-absorb.
    void BeforeSpellHit(Unit* /*caster*/, SpellInfo const* /*spell*/, int32& /*damage or healing*/) { }

    // Called when hit by a spell
    void SpellHit(Unit* /*caster*/, SpellInfo const* /*spell*/) override { }

    // Called when spell hits a target
    void SpellHitTarget(Unit* /*target*/, SpellInfo const* /*spell*/) override { }

    //Called at waypoint reached or PointMovement end
    void MovementInform(uint32 /*type*/, uint32 /*id*/) override { }

    // Called when AI is temporarily replaced or put back when possess is applied or removed
    void OnPossess(bool /*apply*/) { }

    // *************
    // Variables
    // *************

    //Pointer to creature we are manipulating
    Creature* me;

    //For fleeing
    bool IsFleeing;

    // *************
    //Pure virtual functions
    // *************

    //Called at creature reset either by death or evade
    void Reset() override { }

    //Called at creature aggro either by MoveInLOS or Attack Start
    void EnterCombat(Unit* /*victim*/) override { }

    // Called before EnterCombat even before the creature is in combat.
    void AttackStart(Unit* /*target*/) override;

    // *************
    //AI Helper Functions
    // *************

    //Start movement toward victim
    void DoStartMovement(Unit* target, float distance = 0.0f, float angle = 0.0f);

    //Start no movement on victim
    void DoStartNoMovement(Unit* target);

    //Stop attack of current victim
    void DoStopAttack();

    //Cast spell by spell info
    void DoCastSpell(Unit* target, SpellInfo const* spellInfo, bool triggered = false);

    //Plays a sound to all nearby players
    void DoPlaySoundToSet(WorldObject* source, uint32 soundId);

    // Add specified amount of threat directly to victim (ignores redirection effects) - also puts victim in combat and engages them if necessary
    void AddThreat(Unit* victim, float amount, Unit* who = nullptr);
    // Adds/removes the specified percentage from the specified victim's threat (to who, or me if not specified)
    void ModifyThreatByPercent(Unit* victim, int32 pct, Unit* who = nullptr);
    // Resets the victim's threat level to who (or me if not specified) to zero
    void ResetThreat(Unit* victim, Unit* who = nullptr);
    // Resets the specified unit's threat list (me if not specified) - does not delete entries, just sets their threat to zero
    void ResetThreatList(Unit* who = nullptr);
    // Returns the threat level of victim towards who (or me if not specified)
    float GetThreat(Unit const* victim, Unit const* who = nullptr);

    void DoTeleportTo(float x, float y, float z);
    void DoTeleportTo(Position const pos);

    //Teleports a player without dropping threat (only teleports to same map)
    void DoTeleportPlayer(Unit* unit, float x, float y, float z, float o);
    void DoTeleportAll(float x, float y, float z, float o);

    //Returns friendly unit with the most amount of hp missing from max hp
    Unit* DoSelectLowestHpFriendly(float range, uint32 minHPDiff = 1);

    //Returns a list of friendly CC'd units within range
    std::list<Creature*> DoFindFriendlyCC(float range);

    //Returns a list of all friendly units missing a specific buff within range
    std::list<Creature*> DoFindFriendlyMissingBuff(float range, uint32 spellId);

    //Return a player with at least minimumRange from me
    Player* GetPlayerAtMinimumRange(float minRange);

    //Spawns a creature relative to me
    Creature* DoSpawnCreature(uint32 entry, float offsetX, float offsetY, float offsetZ, float angle, uint32 type, uint32 despawntime);

    bool HealthBelowPct(uint32 pct) const { return me->HealthBelowPct(pct); }
    bool HealthAbovePct(uint32 pct) const { return me->HealthAbovePct(pct); }

    //Returns spells that meet the specified criteria from the creatures spell list
    SpellInfo const* SelectSpell(Unit* target, uint32 school, uint32 mechanic, SelectTargetType targets, uint32 powerCostMin, uint32 powerCostMax, float rangeMin, float rangeMax, SelectEffect effect);

    void SetEquipmentSlots(bool loadDefault, int32 mainHand = EQUIP_NO_CHANGE, int32 offHand = EQUIP_NO_CHANGE, int32 ranged = EQUIP_NO_CHANGE);

    // Used to control if MoveChase() is to be used or not in AttackStart(). Some creatures does not chase victims
    // NOTE: If you use SetCombatMovement while the creature is in combat, it will do NOTHING - This only affects AttackStart
    //       You should make the necessary to make it happen so.
    //       Remember that if you modified _isCombatMovementAllowed (e.g: using SetCombatMovement) it will not be reset at Reset().
    //       It will keep the last value you set.
    void SetCombatMovement(bool allowMovement);
    bool IsCombatMovementAllowed() const { return _isCombatMovementAllowed; }

    // return true for heroic mode. i.e.
    //   - for dungeon in mode 10-heroic,
    //   - for raid in mode 10-Heroic
    //   - for raid in mode 25-heroic
    // DO NOT USE to check raid in mode 25-normal.
    bool IsHeroic() const { return _isHeroic; }

    // return the dungeon or raid difficulty
    Difficulty GetDifficulty() const { return _difficulty; }

    // return true for 25 man or 25 man heroic mode
    bool Is25ManRaid() const { return _difficulty & RAID_DIFFICULTY_MASK_25MAN; }

    template<class T> inline
    const T& DUNGEON_MODE(const T& normal5, const T& heroic10) const
    {
        switch (_difficulty)
        {
            case DUNGEON_DIFFICULTY_NORMAL:
                return normal5;
            case DUNGEON_DIFFICULTY_HEROIC:
                return heroic10;
            default:
                break;
        }

        return heroic10;
    }

    template<class T> inline
    const T& RAID_MODE(const T& normal10, const T& normal25) const
    {
        switch (_difficulty)
        {
            case RAID_DIFFICULTY_10MAN_NORMAL:
                return normal10;
            case RAID_DIFFICULTY_25MAN_NORMAL:
                return normal25;
            default:
                break;
        }

        return normal25;
    }

    template<class T> inline
    const T& RAID_MODE(const T& normal10, const T& normal25, const T& heroic10, const T& heroic25) const
    {
        switch (_difficulty)
        {
            case RAID_DIFFICULTY_10MAN_NORMAL:
                return normal10;
            case RAID_DIFFICULTY_25MAN_NORMAL:
                return normal25;
            case RAID_DIFFICULTY_10MAN_HEROIC:
                return heroic10;
            case RAID_DIFFICULTY_25MAN_HEROIC:
                return heroic25;
            default:
                break;
        }

        return heroic25;
    }

    private:
        Difficulty _difficulty;
        bool _isCombatMovementAllowed;
        bool _isHeroic;
};

// WorldBossAI - base for WorldBossAI and BossAI
class GAME_API BossBaseAI : public ScriptedAI
{
public:
    BossBaseAI(Creature* creature);
    virtual ~BossBaseAI() { }

    // Hook used to execute events scheduled into EventMap without the need
    // to override UpdateAI
    // note: You must re-schedule the event within this method if the event
    // is supposed to run more than once
    virtual void ExecuteEvent(uint32 /*eventId*/) { };
    void UpdateAI(uint32 diff) override;

    void SummonedCreatureDespawn(Creature* summon) override;
    void JustSummoned(Creature* summon) override;

    void Reset() override;
    void EnterCombat(Unit* /*who*/) override;
    void JustDied(Unit* /*killer*/) override;
    void JustReachedHome() override;

protected:
    EventMap events;
    SummonList summons;
};

// WorldBossAI - for non-instanced bosses
class GAME_API WorldBossAI : public BossBaseAI
{
public:
    WorldBossAI(Creature* creature) : BossBaseAI(creature) { }
    virtual ~WorldBossAI() { }

    void JustSummoned(Creature* summon) override;

    void EnterCombat(Unit* /*who*/) override;
};

// BossAI - for instanced bosses
class GAME_API BossAI : public BossBaseAI
{
public:
    BossAI(Creature* creature, uint32 bossId);
    virtual ~BossAI() { }

    void JustSummoned(Creature* summon) override;

    void Reset() override;
    void EnterCombat(Unit* /*who*/) override;
    void JustDied(Unit* /*killer*/) override;

    bool CanAIAttack(Unit const* target) const override { return IsInBoundary(target); }

    /**
    * \brief Despawn boss and respawn after 30 seconds.
    *        - Set encounter state to FAIL.
    *        - Reset EventMap & despawns all summons.
    *        - All the functions called throught _EnterEvadeMode() are also called in the respawn process.
    *
    *        - !!IMPORTANT!! -- DO NOT CALL THIS TOGETHER WITH _EnterEvadeMode() THIS COULD CAUSE SOME PROBLEMS WITH THE AI!
    *
    * \ToDo Check compability with vehicles
    */
    void _DespawnAtEvade();

    bool CanRespawn() override;

protected:
    void TeleportCheaters();

    InstanceScript* const instance;
private:
    uint32 const _bossId;
};

#endif // SCRIPTEDCREATURE_H_
